Metal-enhanced fluorescence (MEF) of quantum dots (QDs) and its potential application in microarray-based immunoassays was investigated using silver nanoparticles (AgNPs) prepared by the in situ photoreduction of Ag+ inside a multilayer film consisting of poly(ethyleneimine) (PEI) and hyaluronic acid (HA). UV-Vis spectroscopy, X-ray diffraction, atomic force microscopy, scanning electron microscopy, and transmission electron microscopy confirmed the formation of well-dispersed AgNPs within the multilayer films, the thickness and the amount of which depended on the number of HA layers. Using AgNPs-containing hybrid multilayered films, it was possible to observe the MEF effect of adsorbed QDs, which could be tuned by the thickness of interlayer spacer film prepared of the layer-by-layer assembly of PEI and poly(styrene sulfonate). When the MEF-inducing hybrid film was used as a platform for immunoassay, a significant improvement in the fluorescence signal and sensitivity of the biosensing were observed in the presence of AgNPs in comparison with films that did not contain the nanoparticles.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation (NRF) grant funded by the Ministry of Education, Science and Technology (MEST) (2011-0022709, 2010K001430 “Converging Research Center Program,” and R11-2007-050-03002-0 “Active Polymer Center for Pattern Integration at Yonsei University”).
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Polymers and Plastics
- Colloid and Surface Chemistry
- Materials Chemistry